This invention relates to a capsule containing a dose of a substance for making a drink, as well as to a method for making a drink using the capsule.
Depending on requirements, the substance may be powdered or liquid.
In particular, this invention is for making coffee or other drinks containing coffee (such as cappuccino) using capsules 1 (capsules of this type normally contain a powdered substance). Therefore, reference is preferably made to that type of drink hereinafter. In any case, this invention may be used without distinction for making any other drink using capsules 1.
Moreover, if the substance contained in the capsule is powdered, this invention may be used without distinction for making drinks by means of a method for infusion of the powder using pressurised hot water and/or steam, as well as making drinks when the powdered substance is dissolved by water and/or steam.
At present, there are many types of prior art capsules 1 and apparatuses for making drinks and in particular coffee.
According to a first prior art type, the capsule is relatively rigid and at the moment of making the drink it must be pierced in advance at two points to allow on one side water and/or steam to be fed into it, and on the other the drink to come out.
The main disadvantage of this solution is the fact that it is impossible to make the drink at a relatively high pressure like that required, for example, when making espresso coffee.
In a second prior art type, described for example in patents EP 468 078 and EP 507 905, in contrast the capsule is initially pierced only at its face through which the water and/or pressurised steam are supplied into the capsule. Only at a later stage, when the internal pressure reaches a predetermined level, the bottom of the capsule deforms, tearing against external fixed contact elements which are located a predetermined distance from the bottom of the capsule. At the same time, the rest of the capsule remains unchanged. More particularly, in the case of patent EP 507 905 when the bottom deforms it passes from a concave shape (if seen from the outside) to a flat or even convex shape. In contrast, in the case of patent EP 468 078 the bottom initially has a substantially flat shape and following the pressure increase it adopts a convex shape.
According to a third prior art type, described for example in U.S. Pat. No. 4,136,202, the capsule has a weakened face able to burst when the internal pressure increases. Therefore, in this case operation is similar to that just described, except for the fact that the capsule bursts rather than tearing against one or more fixed spikes.
However, both the second and the third prior art types are not without disadvantages, since capsules 1 for making coffee usually contain a filter able to retain the coffee powder while allowing the drink to come out. The filter is normally positioned close to the wall of the capsule through which the drink comes out. Consequently, all of the methods for using the capsule which involve deformation of that wall may cause movement of and/or accidental damage to the filter which could compromise correct retention of the coffee powder.
A further problem that is significant in commercial terms is the fact that it is impossible to have a single type of capsule which can be used without distinction in machines designed according to different operating logics. In particular, the need is felt to be able to use the same type of capsule both in machines in which delayed opening is achieved by bursting of a wall of the capsule, and machines in which in contrast it is achieved following tearing of the wall against one or more fixed piercing spikes. But that is substantially impossible with the prior art capsules 1.
In this context, the technical purpose which forms the basis of the invention is to provide a capsule containing a dose of a substance for making a drink which overcomes the above-mentioned disadvantages.
In particular, the technical purpose of this invention is to provide a capsule containing a dose of a substance for making a drink which is not subject to the risks of accidental movement of the filter following deformation of its wall through which the drink comes out.
The technical purpose of this invention is also to provide a capsule containing a dose of a substance for making a drink which can be used in machines of various types.
The technical purpose specified and the aims indicated are substantially achieved by a capsule containing a dose of a substance for making a drink as described in the appended claims.